31039891 has 2 divisors, whose sum is σ = 31039892. Its totient is φ = 31039890.

The previous prime is 31039873. The next prime is 31039933. The reversal of 31039891 is 19893013.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31039891 - 2⁵ = 31039859 is a prime.

It is not a weakly prime, because it can be changed into another prime (31039861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15519945 + 15519946.

It is an arithmetic number, because the mean of its divisors is an integer number (15519946).

Almost surely, 2^31039891 is an apocalyptic number.

31039891 is a deficient number, since it is larger than the sum of its proper divisors (1).

31039891 is an equidigital number, since it uses as much as digits as its factorization.

31039891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 31039891 is about 5571.3455286851. The cubic root of 31039891 is about 314.2727524465.

The spelling of 31039891 in words is "thirty-one million, thirty-nine thousand, eight hundred ninety-one".